The author suggests that the famous passage "Refining the language and establishing his sincerity"(Hsiu tz'u li ch'i ch'eng) in the "Wen yen" commentary. I Ching, supposed to have been said by Confucius, has been misread by all Chinese literary theorists and critics for more than two thousand years. They all regarded it as the first and most important Chinese principle of rhetoric. But it is not. The article contains three sections. 　　Section one presents the view of major contemporary Chinese scholars and historians in the field of rhetoric and literary theory, such as Cheng Tien, Ch'en Wang-tao, Kuo Shao-yu, and Lo Ken-tse. They all accepted the traditional interpretation that the passage means “To refine language, its sincerity must be established.” A few contemporary scholars tried to reject this passage as a rhetorical principle, but only on the wrong ground that the original term “hsiu tz'u” does not mean “refining the language”but “mproving culture and education”as suggested by K'ung Ying-ta of the early T'ang dynasty. 　　Section two traces various interpretations of the passage from pre-Ch'in (3rd century B.C.) to the end of the nineteenth century. The Chuang-tzu and the Lun-heng seem to have interpreted the passage, the author suggests, as meaning that in embellishing language and moving the audience one has to show his sincerity. The Literary Mind and the Carving of Dragons written before. A.D 502 by Liu Hsieh (c.465-c. 522) definitely made such an interpretation. This reading has been followed eventually by all later literary theorists and critics, such as Han Yu (768-824), Lin Tsung-yuan (773-819), Pai Chu-i (772-846) of the T'ang dynasty, Chu His (1130-1200) and Li Ke-fei, Yuan Hao-wen (1190-1257) of the Sung-Chin period, down to Yuan Mei (1716-1797), Chang Hsueh-ch'eng (1738-1801), and Ch'en T'ing-cho (1853-1892) of the Ch'ing dynasty. 　　Avery few I Ching scholars, such as K'ung Ying-ta (574-648) of early T'ang and Ch'eng I (1033-1107)of Sung, however, in explaining the meaning of the book read“refining the language” and “establishing his sincerity” in the passage as two separate, parallel phrases. But this interpretation was not made very clear, and had not been recognized and followed by literary critics and writers. James Legge, in his translation of the I Ching did follow this, whereas Richard Wilhelm's later translation accepted the literary critics' reading. In his translation of Chapter 10 of Liu Hsieh's book , Professor Vincent Shih rightfully adopted K'ung Ying-ta's interpretation; but the translation does not seem to coalesce well with Liu's application of the passage. 　　Section three rejects the literary critics' interpretations and suggests that the passage in the I Ching means: a gentleman must refine the language and establish his sincerity in order to secure a career. It does not tell how to refine the language. The interpretations made by literary critics and theorists are wrong for the following reasons (1) From the context in the I Ching, as the author argues with a number of items of evidence, “refining the language”and “establishing his sincerity?are two parallel subjects, which do not have a causatic or goal-means relationship. (2) To interpret the passage as “refining the language to establish its (or his ) sincerity” will violate the Confucian teachings and common moral principles. It also will not be able to achieve the set purpose of securing a career mentioned in the I Ching text. (3) On the other hand, if one interprets the passage in a reverse way as the literary critics and theorists do, i.e.,“to refine the language, one must establish his sincerity,?this meaning will not fit reasonably in the original context (that is,“refining the language”, no matter in what way, cannot be the sole means to secure a career), although the twisted or inferred statement could be, as it is, a true and valuable rhetorical principle. Therefore, the author concludes that such a time-honored interpretation is a misunderstanding of the original text in the I Ching. Or, at best it is a case of inadertently “getting a new meaning by ignoring the original context”and by mis-reading.